In high-k metal gate (HKMG) technology, bias temperature instability (BTI) of a device in an integrated circuit (IC) device is one of the most challenging issues in circuit reliability. BTI may cause degradation of various circuit parameters, such as the linearity, saturation leakage current, threshold voltage, and others. A threshold voltage shift may degrade the reliability of the IC device.
In various reliability tests, high-temperature operating life (HTOL) testing of an IC device is used to assess the durability of the IC device for a period of time under over-heating and over-voltage conditions. Conventional HTOL tests are carried out in the package level, and the HTOL tests generally extend over a long period of time. This results in a serious time bottleneck for improving HTOL performance of an IC device. Thus, there is a need for an early HTOL prediction to speed up the reliability improvement process.